Abstract：
:Clearance indices (clearance of experimental material: clearance of antipyrine, CI) across the perfused human placenta were determined for urea, sodium, and chloride. The selected materials are of relatively small molecular weight and are water soluble. Clearance of urea was determined under conditions of net transfer and of exchange and no difference was detected. Sodium and chloride clearances were measured as exchange rates. The CI were: urea, 0.32 and 0.38 toward fetus and mother, respectively); sodium, 0.28; and chloride, 0.41 (measured toward the fetus). Recalculation of data as the diffusion limitation (LD) facilitated comparison with data in the literature on the monkey, rabbit, and sheep. LD for urea was comparable among the four species whereas the sheep placenta differed, sharply limiting the diffusion of sodium and chloride. The discrepancy in the sheep between urea and sodium indicates that the low transfer rate of the latter cannot be explained by the "thickness" of the syndesmochorial placenta, as is often stated. Inferences concerning nitrogen metabolism in the fetus have been derived by others from data on transplacental urea gradients and urea clearance. Available data in the human are incomplete but are consistent with amino acids providing approximately 10% of fetal energy needs, with glucose serving as the predominant substrate.
journal_name
Am J Obstet Gynecoljournal_title
American journal of obstetrics and gynecologyauthors
Dancis J,Kammerman S,Jansen V,Schneider H,Levitz Mdoi
10.1016/s0002-9378(15)33310-xsubject
Has Abstractpub_date
1981-11-15 00:00:00pages
677-81issue
6eissn
0002-9378issn
1097-6868pii
S0002-9378(15)33310-Xjournal_volume
141pub_type
杂志文章abstract：BACKGROUND:The established method of screening for preeclampsia is to identify risk factors from maternal demographic characteristics and medical history; in the presence of such factors the patient is classified as high risk and in their absence as low risk. However, the performance of such an approach is poor. We dev...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/j.ajog.2018.11.1087
更新日期：2019-02-01 00:00:00
abstract：OBJECTIVE:Our purpose was to evaluate the need for frequent amniotic fluid volume assessments in our antepartum testing unit. STUDY DESIGN:In a retrospective analysis of data accumulated over 1 year in our antepartum testing unit amniotic fluid index values performed at 3- to 4-day intervals were compared with follow-...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/s0002-9378(96)70369-1
更新日期：1996-01-01 00:00:00
abstract：OBJECTIVE:The purpose of this study was to compare bodyweight and composition (percent fat, fat mass, and fat-free mass) in neonates born to mothers with a normal pregravid body mass index (BMI; < 25 kg/m(2)) vs neonates born to mothers with an overweight/obese pregravid BMI (> or = 25 kg/m(2)). STUDY DESIGN:Seventy-t...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/j.ajog.2007.10.796
更新日期：2008-04-01 00:00:00
abstract：:Plasma levels of estrogen were measured daily by radioimmunoassay for 28 consecutive days in 12 healthy euthyroid women and 15 thyrotoxic women (10 with hypomenorrhea and 5 with amenorrhea) before commencement of therapy (except in one case) in an effort to increase understanding of the relationship between the thyroi...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/0002-9378(75)90732-2
更新日期：1975-08-01 00:00:00
abstract：:In vivo proton magnetic resonance spectroscopy of human fetal brain was performed in the third trimester of pregnancy. Spectra were obtained showing signals assigned to cerebral compounds such as N-acetylaspartate, creatine, and cholines. Relative signal intensities were similar to those observed in neonatal brain spe...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/s0002-9378(94)70111-3
更新日期：1994-04-01 00:00:00
abstract：:Highly equivocal results, regarding procedures for the prenatal detection of fetal sexls found in the endocervix, are reported in the literature dating from 1971. The far-reaching genetic and obstetric implications of such procedures led us to investigate endocervical smears from 36 patients (taken during all three t...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/s0002-9378(16)33486-x
更新日期：1975-05-01 00:00:00
abstract：:A single intravenous injection of oxytocin into pregnant sheep (123 to 144 days' gestational age) causes a bout of myometrial activity and an increase in fetal plasma corticotropin levels. We hypothesized that a sustained increased frequency of myometrial contractures accelerates the normal increase in fetal adrenal s...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/0002-9378(92)91859-9
更新日期：1992-01-01 00:00:00
abstract：OBJECTIVE:Our purpose was to evaluate monocyte chemotactic protein-1 in the peripheral blood of women with and without endometriosis. STUDY DESIGN:Fifty-seven patients with endometriosis at laparoscopy done for infertility and pelvic pain were compared with 44 fertile women with no evidence of endometriosis at tubal l...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/s0002-9378(96)70115-1
更新日期：1996-12-01 00:00:00
abstract：OBJECTIVE:The objective of the study was to examine the rates of gestational diabetes mellitus (GDM) associated with both maternal and paternal race/ethnicity. STUDY DESIGN:This was a retrospective cohort study of all women delivered within a managed care network. Rates of GDM were calculated for maternal, paternal, a...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/j.ajog.2010.01.082
更新日期：2010-06-01 00:00:00
abstract：OBJECTIVE:The purpose of this study was to determine the rates of late preterm inductions without a medical indication from birth certificate data and to compare them with rates that were obtained from medical charts. STUDY DESIGN:The Ohio Perinatal Quality Collaborative, which comprises 20 hospitals in Ohio that came...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/j.ajog.2010.07.004
更新日期：2010-09-01 00:00:00
abstract：:This report summarizes the cumulative experience of 3313 pregnancies represented in 59 prospective clinical trials in which intracervical or intravaginal prostaglandin E2 gel was used for cervical ripening before induction of labor. Results indicate that local prostaglandin E2 is superior to placebo or no therapy in e...
journal_title：American journal of obstetrics and gynecology
pub_type： 临床试验,杂志文章,评审
doi：10.1016/s0002-9378(89)80020-1
更新日期：1989-03-01 00:00:00
abstract：:A 35-year-old woman underwent exploratory laparotomy for ovarian enlargement, massive ascites, and intestinal obstruction. Sclerosing peritonitis associated with florid mesothelial hyperplasia, ovarian fibromatosis, and endometriosis were diagnosed postoperatively. We add to the literature this new association of bila...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/s0002-9378(97)70581-7
更新日期：1997-03-01 00:00:00
abstract：:Although previous studies have suggested that the breech infant weighing less than 1,500 gm benefits from cesarean section, the published results have not demonstrated statistically significant differences. We have evaluated pediatric outcome data for 240 breech infants and 525 vertex infants who weighed less than 1,5...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/0002-9378(83)90807-4
更新日期：1983-07-01 00:00:00
abstract：:Sacral neuromodulation with an implanted device is used in patients who experience urinary retention and malfunctioning overactive bladder where conservative treatment is not sufficient. The knowledge of its effect on pregnancy is not known. This article presents the case of a 34-year-old pregnant woman with an implan...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/j.ajog.2014.04.015
更新日期：2014-07-01 00:00:00
abstract：:The immediate postpartum period is a critical moment for contraceptive access and an opportunity to initiate long-acting reversible contraception, which includes the insertion of an intrauterine device. The use of the intrauterine device in the postpartum period is a safe practice with few contraindications and many b...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章,评审
doi：10.1016/j.ajog.2018.07.013
更新日期：2018-09-01 00:00:00
abstract：OBJECTIVE:This study was undertaken to assess the value of minor ultrasonographic markers in predicting significant karyotypic abnormalities. STUDY DESIGN:A total of 2743 fetuses (14-24 weeks' gestation) prospectively underwent a detailed ultrasonographic survey before genetic amniocentesis. Criteria for 8 minor ultra...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/s0002-9378(99)70322-4
更新日期：1999-10-01 00:00:00
abstract：OBJECTIVE:Casual observations of pelvic prolapse have previously been made in adult female squirrel monkeys. We objectively observed and described the pelvic findings of the adult females in our colony to evaluate their potential as an animal model for studies of pelvic relaxation. STUDY DESIGN:Subsets of a group of 2...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/0002-9378(95)90577-4
更新日期：1995-02-01 00:00:00
abstract：:Radical trachelectomy is an effective fertility-sparing treatment for women with early-stage cervical cancer. We describe the first reported ovarian recurrence after radical trachelectomy for stage IB1 adenocarcinoma cervical cancer. ...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/j.ajog.2005.03.071
更新日期：2005-10-01 00:00:00
abstract：OBJECTIVE:The purpose of this study was to investigate the effect of plasma volume expansion on the pulsatility indices of the fetal umbilical and middle cerebral arteries. STUDY DESIGN:Two hundred sixteen patients with severe preeclampsia, HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome, ec...
journal_title：American journal of obstetrics and gynecology
pub_type： 临床试验,杂志文章,随机对照试验
doi：10.1016/j.ajog.2004.06.061
更新日期：2005-01-01 00:00:00
abstract：OBJECTIVE:The aim of this study was to determine whether any association exists between preeclampsia and circulating platelet activating factor levels. STUDY DESIGN:We performed a cross-sectional observational study of circulating platelet activating factor concentrations in nonpregnant women, normotensive pregnant wo...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1067/mob.2000.108894
更新日期：2000-10-01 00:00:00
abstract：:Pre-eclampsia is characterized by uteroplacental ischemia. Prostaglandins can alter systemic blood pressure as well as regulate blood flow to the fetoplacental unit. In the present study, levels of prostaglandin E were significantly decreased in placental tissue from pre-eclamptic patients. Prostaglandin F, a potent v...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/0002-9378(76)90478-6
更新日期：1976-09-01 00:00:00
abstract：OBJECTIVE:Gastroschisis is increasing in many countries, especially among young women. Because young women may have inadequate nutrition, we assessed the relationship between individual nutrients and the risk for gastroschisis. STUDY DESIGN:We analyzed data from the National Birth Defects Prevention Study, a populatio...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/j.ajog.2010.12.053
更新日期：2011-05-01 00:00:00
abstract：:Validity refers to an evidence-based claim about the trustworthiness of decisions made from context-specific performance data. Validity requirements for competency-based assessments in obstetrics and gynecology have not been defined in the literature. We explain why validity is intrinsic to any discussion about compet...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/j.ajog.2011.01.061
更新日期：2011-05-01 00:00:00
abstract：:The relationship between low birth weight, intrauterine growth retardation, and preterm delivery in infants born at a perinatal center is described. Between 20% and 30% of infants born weighing 500 to 2000 gm and nearly 50% of infants born weighing 2001 to 2750 gm had intrauterine growth retardation. For infants withi...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/0002-9378(85)90543-5
更新日期：1985-08-15 00:00:00
abstract：BACKGROUND:In contemporary practice many nulliparous women require intervention during childbirth such as operative vaginal delivery or cesarean delivery (CD). Despite the knowledge that the increasing rate of CD is associated with increasing maternal age, obesity and larger infant birthweight, we lack a reliable metho...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章,多中心研究
doi：10.1016/j.ajog.2017.02.017
更新日期：2017-06-01 00:00:00
abstract：OBJECTIVE:The purpose of this study was to calculate the prospective risk of fetal death in monochorionic-diamniotic twins. STUDY DESIGN:We evaluated 193 monochorionic diamniotic twin pregnancies that were followed and delivered after 24 weeks. Surveillance included cardiotocography and sonography performed at least o...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/j.ajog.2006.01.099
更新日期：2006-07-01 00:00:00
abstract：:Relationships among prepregnancy weight status, prenatal weight gain, and the outcome of 922 twin gestations delivered at term were retrospectively investigated with the use of data provided by linked birth-death certificates in Kansas, 1980 to 1986. Infant birth weights were found to increase linearly with prenatal w...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/0002-9378(90)90845-x
更新日期：1990-01-01 00:00:00
abstract：:Endocrine disrupting chemicals (EDCs) are defined as exogenous chemicals, or mixtures of chemicals, that can interfere with any aspect of hormone action. The field of endocrine disruption is historically rooted in wildlife biology and reproductive endocrinology where EDCs are demonstrated contributors to infertility, ...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章,评审
doi：10.1016/j.ajog.2016.01.182
更新日期：2016-05-01 00:00:00
abstract：OBJECTIVES:The purpose of our study was to establish an in vitro tissue culture system to study eicosanoid metabolism in first-trimester trophoblastic tissue. Thromboxane A2, a potent vasoconstrictor, and prostacyclin, a potent vasodilator, were analyzed to evaluate their production in early pregnancy. STUDY DESIGN:Tr...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章
doi：10.1016/s0002-9378(12)80036-6
更新日期：1992-10-01 00:00:00
abstract：:Observational studies demonstrate that women with severe periodontitis have a higher risk of adverse pregnancy outcomes like preterm birth and low birthweight. Standard treatment for periodontitis in the form of scaling and root planing during the second trimester failed to reduce the risk of preterm or low birthweigh...
journal_title：American journal of obstetrics and gynecology
pub_type： 杂志文章,评审
doi：10.1016/j.ajog.2019.04.029
更新日期：2019-11-01 00:00:00
